1. Field of the Invention
This invention relates to a dental floss, and more specifically, to a dental floss composed of a multifilament of an ultrahigh-molecular-weight polyolefin or an ultrahigh-molecular-weight ethylene/alpha-olefin copolymer and having excellent tensile strength, impact strength, water resistance, creep resistance and use feeling.
This invention also relates to an interdental cleaning tool, and more specifically, to an interdental cleaning tool comprising a taut dental floss composed of a multifilament of an ultrahigh-molecular-weight polyolefin or an ultrahigh-molecular-weight ethylene/alpha-olefin copolymer and having excellent tensile strength, impact strength, water resistance, creep resistance and use feeling.
2. Description of the Prior Art
The dental floss is used to remove food residues or the like between teeth by inserting it therebetween and pulling it strongly with fingers through the teeth.
The conventional dental floss is composed of a crimped nylon multifilament. Since, however, the nylon dental floss has low tensile strength or impact strength, it is frequently broken during use, and it is impossible to clean all interdental parts in the mouth with one dental floss. Furthermore, since it has poor self-lubricating property, it is liable to be caught by teeth and gives an uncomfortable feel of use.
Accordingly, it has been desired to develop a dental floss having excellent tensile strength, impact strength, creep resistance and use feeling.
It has already been known to mold ultrahigh-molecular-weight polyethylene into fibers and tapes, and stretch them to molecularly oriented products having high moduli and tensile strengths. For example, Japanese Laid-Open Patent Publication No. 15408/1981 describes that a dilute solution of ultrahigh-molecular-weight polyethylene is spun and the resulting filament is drawn. Japanese Laid-Open Patent Publication No. 130313/1984 describes that ultrahigh-molecular-weight polyethylene and a wax are melt-kneaded, and the mixture is extruded, cooled and solidified and thereafter stretched. Japanese Laid-Open Patent Publication No. 187614/1984 states that the above molten mixture is extruded, subjected to drafting, cooled and solidified and then stretched.